Weather patterns affect polar sea-ice

Presentation summary for the IPY Science Conference 2010 in Oslo by Professor John Turner

Understanding how polar sea ice responds to global change — whether human induced or as part of a natural process — is really important if scientists are to make accurate predictions about the Earth’s future climate. Scientists at British Antarctic Survey (BAS) reveal that while Arctic sea ice has been decreasing at a significant rate over the last 30 years, sea ice around the Antarctic has increased over the same period.

This slight increase can be explained by changing weather patterns caused by the hole in the ozone layer which has shielded the continent from most of the effects of ‘global warming’, giving a small cooling over the last 30 years.

Sea ice plays a key role in the global environment — reflecting heat from the sun and providing a habitat for marine life. At both poles sea ice cover is at its minimum during summer. However, during the winter freeze in Antarctica this ice cover expands to an area roughly twice the size of Europe. Ranging in thickness from less than a metre to several metres, the ice insulates the warm ocean from the frigid atmosphere above. Satellite images show that since the 1970s the extent of Antarctic sea ice has increased at a rate of 100,000 square kilometres a decade.